I don't know whether there is an easy way for us to directly reuse TimSort in JDK since it's design for sorting objects in an Array, while in Hyracks we don't have explicit object creation and sort everything in main memory. So what I did is that I copied it's source code, and replaced all object assignments/swaps/comparisons using Hyracks in-memory operations.
Best regards, Chen Luo On Sat, Oct 28, 2017 at 12:07 AM, 李文海 <[email protected]> wrote: > I believe reusing jdk afap could be better. btw, timsort is better than > others by 1x when records are locally ordered . > best > > 在 2017-10-28 14:38:21，"abdullah alamoudi" <[email protected]> 写道： > > >While I have no answer to the question of legality, this sounds great. > > > >~Abdullah. > > > >> On Oct 27, 2017, at 9:20 PM, Chen Luo <[email protected]> wrote: > >> > >> Hi devs, > >> > >> I have adapted the TimSort algorithm used in JDK (java.util.TimSort) > into > >> Hyracks, which gives 10-20% performance improvements on random data. It > >> will be more useful if the input data is partially sorted, e.g., primary > >> keys fetched from secondary index scan, which I haven't got time to > >> experiment with. > >> > >> *Before going any further, is it legal to adapt some algorithm > >> implementation from JDK into our codebase? *I saw the JDK implementation > >> itself is adopted from > >> http://svn.python.org/projects/python/trunk/Objects/listsort.txt as > well. > >> > >> Best regards, > >> Chen Luo > > > >
